After this they must then use an adult seatbelt, according to the new rules.

Children must be in an appropriate child car seat until they are either 135cm in height or 12 years old (Image: Getty)

You may be able to choose from more than one type of seat in the group for your child’s weight

Under the new regulations, backless booster cushions available for sale will only be approved for children over 125cm or weighing more than 22kg and they will be clearly labelled as only suitable for children over that height and weight.

A child car seat must:

Conform to the United Nations standard, ECE Regulation 44.04 (or R 44.03) or to the new i-Size regulation, R129. Look for the 'E' mark label on the seat.